Tag Archives: Doomsday

OK, so no one likely actually believed that today was it based on a 5 thousand year old calendar from a long-ago (but quite advanced) civilization. In the spirit of almost everyone blogging about the end of the world today we at PLUS blog figured we’d follow suit and share this post about how the Earth is likely to end at some distant point on the calendar, likely much farther out than 5 thousand years. I encourage you to check out the full post, if only for the really cool pictures. From the blog:

Here Comes the Sun…Seriously

Whether or not the Earth is able to outlast the extremely improbable events listed above, we do know for sure that one day, all life on Earth will likely cease to exist. Ironically, the object that currently sustains life on our planet – the sun – will also be the object that will end it. Allow me to explain.

Currently, our sun is about half-way through its primary life cycle. As mentioned before, stars are so massive that they are able to virtually hold themselves together by the force of their own gravity; however, as the fuel within the sun is slowly converted to light and sent out into space, it will inevitably lose mass, and therefore, gravity. The result of this is the gradual expansion of the sun into what is called a “red giant”. In this phase, the radius of the sun will increase 250 times – well beyond Earth’s current orbit. The loss of gravity, however, could also mean that the orbits of the planets will drift further and further away from the sun, essentially sparing them (except Mercury, which will likely be swallowed by the sun).

Unfortunately, none of that will matter. In the past billion years, the sun has become about 10% brighter and its surface temperature has increased as a result of the natural processes described above. It is likely that billions of years before the sun starts turning into a red giant, the surface temperature on Earth will increase to 60° C (140º F), causing our oceans to virtually evaporate into space. At that point, life on Earth will no longer be able to exist in the natural environment. We will be better off than Venus though – the sun will be so intense that its atmosphere will be blown off into space.

Should you be worried? Hardly: the earliest that the “ocean evaporation” scenario is estimated to begin is in around 500 million years. Still, this means that we came a little late to the party because we could now be inhabiting Earth during the last 10% of its habitable life. There is a bright side, however – assuming that humans spread throughout the galaxy long before this starts to happen, we would probably have the technology to come back to Earth in cool spaceships or something. So, billions of years from now, after the sun has thrown off its outer layers to form a nebula, a human could stand on a cold, rocky Earth, look up into the sky, and see it filled with an image just like this: